PROJECT SUMMARY Despite efforts to prevent chronic diseases, they continue to increase, with underserved ethnic minorities bearing the greatest burden. The United States (US) territory of Puerto Rico (PR) has high prevalence of multiple cardiometabolic conditions that increase risk of cardiovascular disease (CVD). Evidence supports a direct link between psychosocial and food-related environmental risk factors, and cardiometabolic conditions, but these remain markedly understudied at the island-wide population level in PR, despite the clear and pressing need to alleviate the burden of chronic disease in the island. On September 2017, hurricane Maria devastated PR, imposing urgency for studying trends and associations of risk factors for cardiometabolic conditions under times of distress. Thus, the overall goal for this application is to identify trends and longitudinal associations in psychosocial, food-related, and cardiometabolic risk factors that can guide public health priorities and future research needs aimed at reducing CVD-related disparities in PR. To this end, we will establish `PROSPECT: Puerto Rico Observational Study of Psychosocial, Environmental, and Chronic disease Trends', an island-wide, longitudinal population cohort of 2,000 adults (30-75y) in PR recruited with a multi-frame sampling of probabilistic plus community approaches, and assessed in a network of several partner clinics across the island. The study will collect comprehensive data on multiple psychosocial, dietary, and food-related factors, CVD biological markers, and medical record data, with follow-up at 2-years, and will assess variations by urban-rural area and by timing before-after Maria. PROSPECT builds upon the feasibility and resources established by a 2015 pilot study in PR, and emulates the goals and methods of US and Caribbean cohorts inclusive of mainland Puerto Ricans and other Latinos for comparison. Our specific aims are to: (1) estimate baseline and 2y prevalence of psychosocial, diet and food-related environment, and biological CVD risk factors, (2) determine longitudinal associations between 2y changes in psychosocial factors and biological CVD risk factors, (3) determine longitudinal associations between 2y changes in diet and food-related factors, and biological CVD risk factors, and (4) estimate differences in prevalence and 2y changes in risk factors by urban vs. rural area, and pre vs. post-Maria. PROSPECT will identify priorities for addressing CVD risk factors, and will let us plan and implement tailored public health programs and interventions to effectively improve cardiometabolic health in a high-risk, underserved group. The project will enhance collaborative health research, leadership, and capacity in PR, and has high potential for sustainability by using existing infrastructure, and for comparability with US cohorts. Our new island-wide probabilistic comprehensive longitudinal study will bridge a gap in knowledge in PR, create a biorepository and participant database for future use, yield seminal data to support tailored translation into programs and policy, and compellingly reduce disparities in cardiometabolic health in PR.